Deck 13: The Standard 12-Ecg Lead System

Question 1

Which health care professionals commonly obtain the ECGs in many hospitals across the USA?

A) CRTs and RRTs
B) MAs
C) MDs and DOs
D) MLTs

Answer 1

A

Question 2

How many electrodes are used in a 12 lead ECG?

A) 16 electrodes
B) 6 electrodes
C) 12 electrodes
D) 10 electrodes

Answer 2

D

Question 3

Of the precordial leads, which are considered to be the lateral leads?

A) V5 and V6
B) V4, V5, and V6
C) V1, V2, and V3
D) V3, V4, V5 and V6

Answer 3

A

Question 4

What is the correct electrode placement for the modified chest lead?

A) positive electrode at V6, negative electrode on right shoulder or arm
B) positive electrode at V1, negative electrode on left arm or shoulder
C) positive electrode at V2, negative electrode on right shoulder or arm
D) positive electrode at V3, negative electrode on left arm or shoulder

Question 5

When electrical impulses travel toward the positive electrode, what waveform would be recorded on the ECG tracing?

A) negative deflection
B) positive deflection
C) straight line
D) equiphasic deflection

Question 6

What is the standard speed at which ECG systems run?

A) 25 mm/sec
B) 2.5 mm/sec
C) 25 cm/sec
D) 2.5 cm/sec

Question 7

Of the limb leads, which contributes the least amount of information for the 12 lead ECG interpretation?

A) Lead III
B) aVL
C) aVR
D) aVF

Question 8

What does the "a" represent in the unipolar limb leads?

A) abatement
B) attenuation
C) alteration
D) augmentation

Question 9

Which of the following are considered to be precordial leads?
I. Lead I, II, III
II. AVR, aVL, aVF
III. V1, V2, V3, V4, V5, V6

A) I only
B) I and II only
C) I, II, and III
D) III only

Question 10

Of the limb leads, which leads are considered to be the inferior leads?

A) Leads II, III, and aVF
B) Leads I, II, III and aVF
C) Leads II, III, and aVR
D) Leads I, II, III and aVR

Question 11

The electrodes (leads) view the electrical activity of the heart from how many positions?

A) 10
B) 12
C) 8
D) 9

Question 12

Which leads monitor the electrical activity in the frontal plane of the heart?
I. Limb leads
II. Precordial leads
III. Modified Chest Lead

A) I and II only
B) I only
C) II only
D) I and III only

Question 13

When electrical impulses travel away from the positive electrode, what would be recorded on the ECG tracing?

A) negative deflection
B) straight line
C) positive deflection
D) equiphasic deflection

Question 14

What are the normal ECG configurations composed of?
I. waves
II. Complexes
III. Segments
IV. Intervals

A) I and II only
B) II, III, and IV only
C) II and III only
D) I, II, III, and IV

Question 15

Of the precordial leads, which are considered to be the anterior leads?

A) V4, V5, and V6
B) V1, V2, and V3
C) V5 and V6
D) V1, V2, V3, and V4

Question 16

On ECG paper operating at standard speed, what is the duration of the large squares?

A) 0.2 seconds
B) 0.04 sec
C) 2 seconds
D) 0.4 sec

Question 17

Which limb leads are considered to be the bipolar leads?

A) I, II, and avL
B) II and aVL
C) III and aVL
D) I, II, and III

Question 18

What is the name of imaginary equilateral triangle formed by the axes of the limb leads?

A) Einthoven's
B) Entwhistle's
C) Entemann's
D) Eiserman's

Question 19

What waveform is recorded on an ECG tracing when an electrical impulse travels perpendicular to the lead axis?

A) sawtooth
B) negative
C) positive
D) equiphasic

Question 20

On an ECG tracing, what is an isoelectric line called?

A) interval
B) segment
C) waveform
D) complex

Question 21

In a healthy adult at rest, what is the normal duration of the PR Interval?

A) 0.20 - 0.26 sec
B) 0.12 - 0.20 sec
C) 0.04 - 0.08 sec
D) 0.08 - 0.12 sec

Question 22

Which portion of an ECG tracing represents atrial depolarization?

A) T wave
B) QRS complex
C) U wave
D) P wave

Question 23

Which low voltage wave may become more prominent in the presence of electrolyte disturbances, heart disease, or certain medications?

A) T wave
B) Y wave
C) P wave
D) U wave

Question 24

What portion of the RR interval does the QT interval normal compose?

A) 60%
B) 40%
C) 20%
D) 30%

Question 25

What does a flat ST segment usually indicate?

A) disconnected electrode
B) hyperkalemia
C) ischemia
D) normal ECG tracing

Question 26

Which portion of the ECG tracing represents the time between ventricular depolarization and repolarization?

A) PR interval
B) ST segment
C) T wave
D) QRS complex

Question 27

Which portion of the ECG tracing represents total ventricular activity?

A) T wave
B) QRS complex
C) QT interval
D) U wave

Question 28

Which portion of the ECG tracing represents ventricular repolarization?

A) U wave
B) QRS complex
C) ST interval
D) T wave

Question 29

Which portion of the ECG tracing represents ventricular depolarization?

A) T wave
B) P wave
C) PR interval
D) QRS complex